21779043 has 16 divisors (see below), whose sum is σ = 34116096. Its totient is φ = 12183840.

The previous prime is 21779033. The next prime is 21779063. The reversal of 21779043 is 34097712.

It is not a de Polignac number, because 21779043 - 2⁵ = 21779011 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 21778995 and 21779013.

It is not an unprimeable number, because it can be changed into a prime (21779003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24955 + ... + 25812.

It is an arithmetic number, because the mean of its divisors is an integer number (2132256).

Almost surely, 2^21779043 is an apocalyptic number.

21779043 is a deficient number, since it is larger than the sum of its proper divisors (12337053).

21779043 is a wasteful number, since it uses less digits than its factorization.

21779043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50794.

The product of its (nonzero) digits is 10584, while the sum is 33.

The square root of 21779043 is about 4666.8022242216. The cubic root of 21779043 is about 279.2626988345.

The spelling of 21779043 in words is "twenty-one million, seven hundred seventy-nine thousand, forty-three".